论文标题
相对论能量密度理论中的磁四极转变
Magnetic quadrupole transitions in the relativistic energy density functional theory
论文作者
论文摘要
背景：磁四极（M2）激发代表了与自旋和轨道过渡算子引起的与核磁化相关的原子核的基本特征。到目前为止，它仅在非权威主义理论方法中进行了研究，并且可用的实验数据相当有限。目的：我们旨在使用相对论核能密度功能的框架研究封闭和开放壳核中M2转变的性质。计算出的M2过渡强度可用于限制自旋旋转磁因子的淬火。方法：使用相对论的准粒子随机相近似（RQRPA）描述了M2激发，其残留相互作用与等异源性相关术语扩展。结果：描述并分析了M2转变强度分布的封闭和开放壳核。将结果与可用的实验数据进行了比较，并讨论了实验中缺少的强度。在$^{36-64} \ rm CA $同位素链中研究了M2过渡属性的演变。结论：主要的M2转换具有相当丰富的潜在结构，并且由于较大的构成粒子孔构型，其集体性随质量数的增加而增加。开放壳核中的配对相关性具有很强的作用，从而导致M2强度降低并将质心能量转移到更高的值。 M2过渡强度的分析表明，可能缺少大量的实验强度，这主要是由于限制了相当受限制的能量范围。 CA同位素计算出的M2强度以及未来的实验数据将允许限制核培养基中$ G $因子的淬火。
Background: Magnetic quadrupole (M2) excitation represents a fundamental feature in atomic nucleus associated to nuclear magnetism induced by spin and orbital transition operator. So far it has only been investigated within the non-relativistic theoretical approaches, and available experimental data are rather limited. Purpose: We aim to investigate the properties of M2 transitions in closed and open-shell nuclei using the framework of relativistic nuclear energy density functional. The calculated M2 transition strengths could be used to constrain the quenching of the spin gyromagnetic factors. Methods: The M2 excitations are described using the relativistic quasiparticle random phase approximation (RQRPA) with the residual interaction extended with the isovector-pseudovector term. Results: The M2 transition strength distributions are described and analyzed for closed and open shell nuclei. The results are compared with available experimental data and the strength missing from the experiment is discussed. The evolution of M2 transition properties has been investigated within the $^{36-64} \rm Ca$ isotope chain. Conclusion: The main M2 transitions have rather rich underlying structure and their collectivity increases with the mass number due to larger number of contributing particle-hole configurations. Pairing correlations in open shell nuclei have strong effect, causing the M2 strength reduction and shifting of the centroid energies to higher values. The analysis of M2 transition strengths indicate that considerable amount of experimental strength may be missing, mainly due to limitations to rather restricted energy ranges. The calculated M2 strengths for Ca isotopes, together with the future experimental data will allow constraining the quenching of the $g$ factors in nuclear medium.
